Matthew d’Ancona warns in today’s Sunday Telegraph against “a flowering of Right-wing Bennism” inside the Tory Party. One can see what he means: if the party turns inwards, and consumes itself in factional strife about ideological questions which are of little or no interest to most voters, it will never again win a general election.

Sectarian warfare, in which one forgets the enemy and concentrates on defeating those on one’s own side who fail to exhibit perfect doctrinal purity, is an unattractive spectacle. That way lies self-righteous irrelevance followed by oblivion.

But it ought to be perfectly possible to conduct political arguments without becoming narrow, bitter and exclusive. As Mark Wallace suggests in his post today for ConHome from the Freedom Association in Bournemouth, we need places where reasonable people can meet and discuss what we have in common.

And perhaps I could suggest that the Tory Party remains such a place. It is easy to become too gloomy about this kind of thing. The fact that the party contains people who do not agree in every particular about what should be done about the great issues of the day is actually a source of strength. Conservatives should make a virtue of being a bit more relaxed about differences of opinion. It is on balance a strength to have Bill Cash and Ken Clarke in the same party. The Conservative tradition allows a certain latitude in these matters. It can venerate Margaret Thatcher, despite her having signed the Single European Act, and Winston Churchill, despite his having been for 20 years a Liberal.

While living in Germany in the 1990s, I watched aghast as that country’s political class refused to have the necessary argument about whether or not to replace the national currency with the euro. There was no doubt that the German people wished to keep the German mark, proud symbol of post-war recovery: to them it was palpably absurd to share a currency with, for example, the Italians. But on 23 April 1998, the country’s MPs voted by 575 to 35 in favour of scrapping the mark and bringing in the euro. All but eight of the “no” votes came from the PDS, successor to the East German communist party. Among politicians in what had once been West Germany, there was no proper attempt to argue the case against joining the euro.

In a parliamentary system, MPs have the right (as Edmund Burke pointed out) to defy public opinion. But when they refuse even to examine the arguments which they propose to overrule, that right becomes less defensible.

It is to the credit of British Conservatives that they have been prepared to have the necessary argument about Europe, and about how (if at all) it can be reconciled to our tradition of self-government. This debate is highly inconvenient to whoever is party leader, but suppressing the argument is generally even worse. This is perhaps another way of saying that while I respect the sincerity of those Tories who have joined UKIP, I wish they had felt able to go on arguing their case inside the Conservative Party.